Digitizer systems are used as computer input devices for capturing data or handwritten signatures, text, drawings, symbols and the like. Digitizing tablets and touch screens are exemplary digitizer systems used to replace a mouse as a primary pointing and navigation device for desktop computers. A user interacts with the digitizer system by positioning and moving an object such as stylus and/or a finger over a sensing surface of the system, e.g. a tablet and/or a touch screen. Position of the object with respect to the sensing surface is tracked by the digitizer system and interpreted as a user command.